mssailormouth

This page lists questions and answers that were posted by visitors named mssailormouth.

Questions

The following questions were asked by visitors named mssailormouth.

A ball is thrown straight up from a bridge at a speed of 11.0 m/s. What will be its velocity (speed and direction) after 2.0 seconds?

A ball is thrown straight up from a bridge at a speed of 11.0 m/s. If it takes 5.5 seconds to hit the water below, what is the velocity just before it hits the water?

A sprinter accelerates at 5.0 m/s2. How far will she travel in 4.0 seconds if she starts at 0 m/s?

A runner travels 1.65 km in 5 min and 30 seconds. What is the velocity in m/s? Answer to two decimal places. I think I have answer since v=d/t convert 5 min 30 sec to seconds 330 seconds and 1.65km to 1650m 1650m/330sec answer: 5m/s Am I right?

A car moving at 22.0 m/s accelerates at 3.00 m/s2 for 2.39 seconds. What will the final speed be in m/s? do I use v subf= at+v sub0 3.00x2.39 +22.0= answer 29.17??

A car traveling at 22.0 m/s accelerates for 2.37 seconds at a rate of 2.25 m/s2. How far will it travel in meters during this time? (22.0)(2.37) +1/2(2.25)(2.37)= answer 58.5m right?

A car traveling at 22.0 m/s decelerates for 2.33 seconds at a rate of -2.25 m/s2. What will the final speed be in m/s? =16.8m/s??

A rock dropped from a bridge takes 3.21 seconds to hit the water. How high is the bridge in meters? I need to find Vsub0 to be able to calculate h....but how do I get Vsub0???

An airplane is flying at 95.0 m/s when the engine is turned off. As it glides, it experiences a force of drag so that is slows down at -0.700 m/s2. How far in meters will it travel in 1.00 minute ? answer: 4440m??

A runner can run a 400.0 meter lap in 50.0 seconds. He finishes at the same spot as he began. What is his average velocity?

A car accelerates from 0.0 to 33 m/s in 6.0 seconds. What is the magnitude of the acceleration? I got 198 but the answer is 5.5?? Not understanding this.

The acceleration due to the Earth's gravity, in English units, is 32 ft/s2. In the absence of air friction, a ball is dropped from rest. Its speed on striking the ground is exactly 60 miles/hr. For what time interval was the ball falling? I am unsure how...

Suppose you throw a ball vertically upward with a speed of 49 m/s. Neglecting air friction, what would be the speed of the ball 2.0 second later?

An object has a mass of 24.0 kg and is accelerated horizontally at 4.0 m/s2. What is the force required?

A croquet ball that is hit by a bat keeps rolling horizontally after it leaves the bat because of

An elevator has a mass of 1200.0 kg. It is rising at a steady speed of 3.00 m/s. What is the tension in the cable lifting the elevator? so T=mg + ma m=1200.0kg g=9.8 m/s^2 a=?? I'm not sure how to get acceleration from what is given.

An elevator has a mass of 1200.0 kg. It is rising at a steady acceleration DOWNWARD of -3.00 m/s2. What is the tension in the cable lifting the elevator? T=1200.0x9.8 +1200.0x-3600 =8160N right?

A water balloon with a mass of 1.20 kg is falling from a roof. If the average force of friction is 0.500 N, what is the acceleration on the balloon in m/s2? I am not sure how to get started

What is the mass of a car that weighs 11,220 N? (The units are kg. Do not include units in the answer and you may round to 3 significant figures. ) so w=mg 11220=m9.80 11220/9.80=m 1144=m to three sig figures =1140 kg right?

A man has a mass of 77.0 kg and is accelerating upward in an elevator at 2.50 m/s2 What is the normal force on his feet in newtons? 77.0kg x2.50m/s^2 + 77.0kg x 9.80m/s^2 = Answer: 947 N??

A 1600 kg car moving at 22 m/s is in a wreck with a 2900 truck moving at 32 m/s in the opposite direction. Which exerts a greater magnitude of force on the other?

A baseball is thrown horizontally from a height of 6 meters at a speed of 24 m/s. How far will it travel horizontally before it hits the ground?

A golf club head can be thought of as undergoing circular motion when you swing the club. If the club head has a mass of 0.65 kg, a speed of 24 m/s and a radius of 2.2 meters, (club length + arm length) what is the force on the club head due to the swing?

A racecar driver has to hold on tightly when going around a banked curve. Approximately what is the centripetal force on a 2,540.0 kg car going around a circle with a diameter of 190.0 meters at 25.0 m/s?

A racecar driver has to hold on tightly when going around a banked curve. How many "gs" does the driver experience in a 2200 kg car going around a circle with a radius of 95 meters at 25 m/s?

A forensic scientist (CSI) is trying to find a weapon thrown off a bridge into the lake. Assume it is thrown horizontally and it sinks straight down once it hits the water. The bridge height is 15 meters and a normal throwing speed is 23 m/s. How far from...

A 600.0 kg roller coaster is going around vertical loop with a radius of 10.0 meters. The speed of the coaster is 14m/s at the top of the loop. What it the magnitude of the CENTRIPETAL force on the roller coaster, to the nearest whole number of newtons? F...

A basketball player throws a 1.2 kg ball 15 meters into the air. What is the increase in potential energy? What is the work done by the player? Is the answer the same for each, because I'm getting the same answer but I feel like something is wrong... 176J

A toy "spring gun" has a spring with a spring constant of 30,000 N/m and is depressed 4 cm. It shoots a plastic dart with a mass of 45 grams. How fast will the dart travel if there is no friction?

In an auditorium, a physics teacher uses a pendulum made by hanging a bowling ball from a wire to the ceiling. At the low point in its swing, a ball with a mass of 7.2-kg has a speed of 6 m/s. Ignoring air resistance, how high will the bob swing above the...

A roller coaster with a mass of 500.0 kg starts from a height of 27.0 meters with a speed of 5.1 m/s. It descends to a height of 2.00 meters before it starts back up. Some energy is loss to the work due to friction. The speed at the bottom of the ramp is...

A 10 kg rock that has been dropped from a 60 meter high cliff experiences a average force of air resistance of 30 N. Calculate the KE at the bottom of the fall.

A force of F = 125 N is used to drag a crate 3.0 m across a floor. The force is directed at an angle upward from the crate so the vertical part of the force is Fv = 65 N and the horizontal part of the force is Fh = 107 N. How much work is done on the box?

A roller coaster with people on board has a total mass of 4500 kg and starts at a height of 22 meters with a speed of 2.0 m/s. 50 kJ of work is done by friction on the way to the bottom of the ride. What is the speed at the bottom of the ride?

A 2200 kg car can accelerate from 0 to 30.0 m/s in 5.5 seconds. What is the power required?

An object with a kinetic energy of 50 J is stopped in a distance of 0.01 m. The average force that stops the object is??

If the speed of a car is doubled, the work to stop the car changes by a factor of so it's 4....but I cannot think of how I know it is double. Any explaination?

Is it possible for a slower moving person to produce a higher horsepower than a faster moving person? If so under what circumstances? Why or why not?? I would think a slower moving person carrying a heavier weight could produce higher horsepower. this que...

If you double the speed of a car, how much does the kinetic energy increase? How do you know?

A 10 kg rock that has been dropped from a 60 meter high cliff experiences a average force of air resistance of 30 N. Calculate the KE at the bottom of the fall. so KE=PEgravity 5880 is the PE but no friction force deducted...do I just subtract 30N? my boo...

A projectile is launched horizontally from a height of 2.2 meters at 35 m/s. How far will it travel horizontally before it hits the ground?

What is the formula for NORMAL force?

A bullet of mass 0.010 kg and speed of 100 m/s is brought to rest in a wooden block after penetrating a distance of 0.10 m. The work done on the bullet by the block is so my answer is 50 but I'm getting it wrong? I don't understand why?? work=KE 1/2(.010)...

An impulse of 15 Ns acts on a 0.2 kg ball initially at rest. What is the change in momentum? momentum =mV how do I get to V I am given m=0.2kg F=ma 15=0.2a a=75m/s do I need to time t next? i'm so lost :(

A ball traveling with an initial momentum of 4.5 kgm/s bounces off a wall and comes back in the opposite direction with a momentum of –3.5 kgm/s. What is the change in momentum? Answer: -3.5-4.5= -8 kgm/s?

An impulse of 15 Ns acts on a 0.2 kg ball initially at rest. What is the final speed?

In the first step of nuclear fission, a U-235 atom absorbs a neutron and becomes U-236 before becoming unstable and breaking into two smaller atoms and emitting various energies and particles. The mass of the U-235 is 235 amu and the mass of the neutron i...

A 2.0 kg lab car moving to the right with an initial velocity of 3.0 m/s collides with a 1.0 kg lab car moving to the left with a velocity of 8.0 m/s in a inelastic collision. What us the final velocity? Take left to be negative.

A 12000 kg train engine moving at 2.2 m/s locks into 3 boxcars with a total mass of 25000 kg sitting still. If the collision is inelastic and has little friction, how fast will the engine and cars move? I got 1.4 but correct answer is 0.71? I don't unders...

Trying to understand what happens to KE in an inelastic collision. I know it is not conserved. Does that mean it is lost? But if energy is neither created or destroyed....how can KE be just lost? I am confused.

What is meant by KE being lost to the system in an inelastic collision?

When a baseball bat hits the ball, the impulse delivered to the ball is increased by is it "follow through"??

A ball is dropped down to the floor and bounces back up to the same height. (we are assuming a "perfect" ball.) What is the change in the momentum? the change would be ZERO right? If the momentum was zero to begin with then there is zero change.

A truck of mass 4000 kg is at rest, but free to roll with no resistance. If you push it forward with a force of 500 N, the momentum at the end of 5 s of pushing will be force=delta p/ delta t 500= delta p/5 p=2500?? right?

A 4 kg block, initially moving due east at 3 m/s, is acted upon by an impulse having magnitude 8 Ns and direction due west. The final velocity of the block is I keep getting this problem wrong. ok so momentum =massVelocity 3x4 =12kgm/s=impulse force delta...

Two people sitting on rolling chairs with little friction push off from each other so that they move apart. On is 60 kg and one is 40 kg. If the 40 kg person recoils at 4.3 m/s, what will the veloocity of the 60 kg person's recoil in m/s mivi=mfvf 40v...h...

A rod has a pivot point on the left end, one force of 6 N up in the middle and one force of 3 N up on the right end. Can the system be at equilibrium? Explain. The book assigned for my course has 6 sentences on equilibrium. None of which discuss how one w...

A force of 25 N is on the end of a 4 meter lever arm turning clockwise. What is the torque? so CW is neg so 25*-4=-100Nm right?

A weight of 15 N is located at a distance of 2.5 meters from the fulcrum of a simple lever. At what distance from the fulcrum should a weight of 20.0 N be placed on the opposite side of the fulcrum to balance the system?

How so I solve for Torque 2 mass? Torque 1= .125Nm Torque 2= mass? x 9.80 m/s^2 x .253m

Answers

The following answers were posted by visitors named mssailormouth.

is a gravity? 9.80m/s^2

I did calc t^2 didn't write it though d=Vsub0t +1/2at^2

is it -9.80 x 3.21= -31.458 is Vsub0??

accck ok so 1/2(9.80)(3.21)^2= 50.5 m

I'm learning slowly but surely!

wow...thanks I always find myself getting stumped when I have problems with steady speed. I need to remember this!

so if 1200 x 9.8= 11760 the answer choices provided are 11800 15400 8160 3600 I'm assuming 11800 is the answer the professor wants us to round to 3 significant figures??

whoops 1200x-3.00=-3600

1.20kg x 9.80 m/s^2= 11.76-0.500=11.26 11.26=1.20a a=9.38 m/s^2??

I'm not really grasping this concept well. I don't know if the KE of the dart is equal is the PE stored? Based on the formulas I don't know that is correct. PE= 1/2kx^2 k=30,000 x=4cm KE= 1/2mv^2 m=45g v=0??

ooooh for some reason I thought I needed to subtract PE and KE and it wasn't making any sense.

It's actually so simple. I am waaaaaaaaaay over thinking these problems thanks! 6^2 /2(9.80)= 1.8m

I'm not getting any correct answers with this formula....I'm not sure what I'm doing wrong here 1/2(0.5)(5.1)^2 top 1/2(0.5)(22.0)^2 bottom what?

mgh does not help me I don't know what it means

my book says PE gravity= mgh this is why I'm getting confused my book calls mgh PE and you say KE??

ok so KE=PE gravity which is mgh - h x friction force (10*9.80*60)-(60*30) =4080 J

how do I calculate friction?

KE top + PE top -energy lost to friction (L)=KE bottom + PE bottom 500*9.8*27 + 1/2(500)*5.1^2 =138802.5 500*9.8*2 + 1/2(500)*22^2 = 130800 138802.5-L=130800 138802.5=130800+ L 138802.5-130800=L 8002 J lost to friction

solve graphically search youtube vector lab part 1 phys 1030

I have to get better about reading the question and figuring out what I need to know, then determining what I need to find in order to find the solution. I just look at it and panic and think I don't have all of the information to do it. thanks! a= 30/5.5...

KE=work work=fd force=w/d 50/0.01= answer: 5000N

so 60 x 30 5880-1800=4080

1/2(7.2)(6^2)=7.2(9.8)h h=1.8

I've got a huge number this cannot be right. 1/2(4500)(2.0)^2 + 4500(9.8)(22)-50000=929200?????

KE bottom KE top=PE top -friction 1/2(4500)v^2=4500(9.8)(22) -50000 v=20

well how do I figure how much work the wood block did on the bullet??

Ok so my professor FINALLY responded to me and said the answer is -50 J not 50J with no explanation. What variable would I make negative to produce that answer? Would the velocity by negative since the wood is stopping the bullet?

ok! finally some clarity. thank you!

what is dP? this chapter in my book doesn't use the letter d? 15=0.2v v=75?

75 m/s is the speed....so the momentum is the 15N?? or 15kgm/s??

Is the impulse also -8 or is the impulse positive 8?

so I should set this up at initialV=combined and divided by the combined mass That's where I'm messing it up. thanks

I am in an intro physics course, online as a pre-req no on site classes were available and my professor chose a crap book with little explaination and then just assigns us to read the book then answer question...so I must turn to the internet for help bec...

or is it 4.3 m/s=-60v v=-.071??

I was reading the problem that the 40kg recoiled in 4.3 seconds. I'm tired :(

if they are both going up and CCW then they are both positive so no cancel?

1.875 so about 1.9m

this is what professor wrote I have no idea how to go about solving m1*g*L1=m2*g*L2 m1=.1016kg gravity 9.80m/s^s L1= .126m m2? L2 =.253m

I just figured it out a few minutes ago. .1016x.126=.0128016/.253=.05059 or .0506kg