1) Read the scenario.

A car starts 10 m north of a reference point. It moves at a constant velocity over the next 5 s, reaching a position of 10 m south of the reference point.

What is the car’s average velocity?

0 m/s
4 m/s north
2 m/s south
4 m/s south

-I know that v=d/t but I do not know what to do after I get 2 m/s n with it reaching a position of 10 m south of the reference point.

2)
A 60 kg skydiver is falling at a terminal velocity of 50 m/s.

Calculate the amount of gravitational force acting on the skydiver.

3000 N
9.8 N
588 N
0 N

Could anyone help with the equation I would need to do for this one?

3)
Study the scenario.

An ice block in motion begins to slide up an icy hill. The system consists of the block, the hill, and the Earth. (There is no friction.)

Which choice best describes the changes in kinetic and potential energy?

The kinetic energy remains constant as the block moves up the hill because its speed remains constant. The potential energy increases because the block’s height relative to its starting position increases. The total energy increases.
The kinetic energy decreases as the block moves up the hill because it slows down. The potential energy increases because the block’s height relative to its starting position increases. The total energy remains constant.
The kinetic energy remains constant as the block moves up the hill because its speed remains constant. The potential energy remains constant because the block remains on the ground the entire time. The total energy remains constant.
The kinetic energy increases as the block moves up the hill because it speeds up. The potential energy increases because the block’s height relative to its starting position increases. The total energy increases.

I think its D, but I am not sure.

1 answer

1) To calculate the average velocity, consider the total distance traveled and total time. The car started 10 m north and ended up 10 m south, so the total distance traveled was 20 m. The time taken was 5 s. So, the average velocity is:

v = d/t = 20m / 5s = 4 m/s

Since the car moves from north to south, the correct answer is 4 m/s south.

2) To calculate the gravitational force acting on the skydiver, use the equation:

F = m * g

where F is the gravitational force, m is the mass of the skydiver, and g is the acceleration due to gravity (approximately 9.8 m/s²).

F = 60 kg * 9.8 m/s² = 588 N

So, the gravitational force acting on the skydiver is 588 N.

3) The correct answer is:

The kinetic energy decreases as the block moves up the hill because it slows down. The potential energy increases because the block’s height relative to its starting position increases. The total energy remains constant.

As the block moves up the hill, it loses kinetic energy (it slows down) but gains potential energy (due to increased height). In a frictionless system, the total mechanical energy (kinetic + potential) remains constant.