Answer:
option c
Explanation:
Kinetic energy is due to the speed of a body.
When speed is doubled, the kinetic energy is quadruple.
From third equation of motion, braking distance is also proportional to square of speed. Thus, when speed is doubled, the braking distance is quadruple.
Thus, option c is correct.
6x2=12m
6x18=108
12m+108
Simplified: m+9 bc 12/12 and 108/12
Answer:
2 m/s^2
Explanation:
from the question
v=15 m/s
t=7.5
a=?
from the first equation of motion
v=u+at
where,
v=final velocity
u=initial velocity
a=acceleration
t=time
from the question (u) will be zero because the body started at rest
v=u+at
15=(0)+a×7.5
15=7.5a
a=15/7.5
a=2 m/s^2
Answer:
25lb
Explanation:
You haven't changed (you are made up of the same atoms), but the force exerted on you is different. Physicists like to say that your mass hasn't changed, only your weight.
Answer:
210
Explanation:
A ball rolls horizontally off the cliff at a speed of 30 m/s. It takes 7 seconds for the ball to hit the ground. What is the height of the cliff and the horizontal distance traveled by the ball?
S = (1/2)*9.8 m/s^2 * 7^2 = 240.1 m if the ball is very dense so air resistance, and therefore terminal velocity, can be ignored.
S = v * t = 30 m/s * 7 s = 210 m for the horizontal distance, again assuming negligible air resistance.
