The formula of the kinetic energy is:

where m is a mass of the object, v is speed of the object at the moment of time. So we have:

The answer is
2000 Joules.
<u>Note that</u>:
The gravitational potential energy = 
where m: is the mass, g: the acceleration due to the gravity and h is the height from the earth surface
Then, we can increase the gravitational potential energy by increasing the mass or the height from the earth surface
<u>In our question</u>, we can increase the gravitational potential energy by
<u>A) Strap a boulder to the car so that it wights more.</u>
Because gravity has been known to define as a force of attraction between things that have mass.
Answer:
Option B
Explanation:
Speed of a wave is denoted by:
v=fλ
where f is the frequency which is unchanged 15Hz and λ is the new wavelength which is 28m
v=fλ

Answer:
B)velocity of object decreases
Explanation:
Consider the positive x axis as positive direction
Assume a body moving in negative x-axis direction
It's acceleration also alone negative x-axis direction
So according to our consideration
velocity and acceleration values are negative
That is both are towards negative x direction
But as both velocity and acceleration are in same direction, MAGNITUDE of velocity increases
But as magnitude increases in negative direction, velocity value decreases
But speed value increases(As speed is scalar and velocity is a vector)