A motor cyclist travelling at 12m/s decelerates at 3m/s square

a) how long does he take to come to a rest
b) how far does he travel in coming to rest

User Icon for Damon Damon answered
9 years ago

average speed during stop = 12/2 = 6

v = Vi - a t
0 = 12 - 3 t to stop (get v = 0)
so
t = 12/3 = 4 seconds to stop

distance = average speed * time
= 6 * 4
= 24 meters

User Icon for Clown Bot Clown Bot answered
1 year ago

a) The motorcyclist is decelerating at a rate of 3 m/s². To find the time it takes for him to come to a rest, we can use the equation v² = u² + 2as, where v is the final velocity (0 m/s in this case), u is the initial velocity (12 m/s), a is the acceleration (-3 m/s²), and s is the distance traveled.

Plugging in the values, we get 0² = 12² + 2(-3)s. Simplifying, we have 0 = 144 - 6s. Rearranging, we find 6s = 144. Dividing by 6, we get s = 24.

So, it takes the motorcyclist 24 seconds to come to a rest.

b) To find the distance the motorcyclist travels in coming to rest, we can use the equation v² = u² + 2as again.

Plugging in the values, we get 0² = 12² + 2(-3)s. Simplifying, we have 0 = 144 - 6s. Rearranging, we find 6s = 144. Dividing by 6, we get s = 24.

Therefore, the motorcyclist travels a distance of 24 meters in coming to rest.

User Icon for Step-by-Step Bot Step-by-Step Bot answered
1 year ago

To solve these questions, we can use the following equations of motion:

1) v = u + at - Equation 1
2) s = ut + (1/2)at^2 - Equation 2

Where:
- v is the final velocity (0 m/s, as the motorcyclist comes to rest)
- u is the initial velocity (12 m/s)
- a is the acceleration (deceleration in this case, -3 m/s^2)
- t is the time taken (unknown)
- s is the distance traveled (unknown)

a) To find the time taken to come to rest, rearrange Equation 1 to solve for t:

v = u + at
0 = 12 + (-3t)
-12 = -3t
t = 4 seconds

Therefore, it takes the motorcyclist 4 seconds to come to rest.

b) To find the distance traveled, rearrange Equation 2 to solve for s:

s = ut + (1/2)at^2
s = 12(4) + (1/2)(-3)(4)^2
s = 48 - 24
s = 24 meters

Therefore, the motorcyclist travels a distance of 24 meters in coming to rest.

User Icon for Explain Bot Explain Bot answered
1 year ago

To answer these questions, we can use the equations of motion for uniformly decelerated motion.

a) To find how long the motorcyclist takes to come to a rest, we can use the equation:

v = u + at

where:
v = final velocity (0 m/s, since the motorcycle comes to a rest)
u = initial velocity (12 m/s)
a = acceleration (deceleration, -3 m/s²)
t = time

Rearranging the equation to solve for time (t), we get:

t = (v - u) / a

Substituting the given values, we can calculate the answer:

t = (0 - 12) / (-3)
t = 4 seconds

Therefore, it takes the motorcyclist 4 seconds to come to a rest.

b) To determine how far the motorcyclist travels while decelerating, we can use the equation:

s = ut + (1/2)at²

where:
s = distance
u = initial velocity (12 m/s)
t = time (4 s, as calculated in part a)
a = acceleration (deceleration, -3 m/s²)

Plugging in the values:

s = (12)(4) + (1/2)(-3)(4)²
s = 48 - 24
s = 24 meters

Therefore, the motorcyclist travels a distance of 24 meters while coming to a rest.