Answer: 500 joules
Explanation:
Given that
Mass of ball = 10kg
kinetic energy = ?
velocity of the ball = 10m/s
Kinetic energy is the energy possessed by a moving object. It is measured in joules, and depends on the mass (m) of the object and the velocity (v) by which it moves
i.e K.E = 1/2mv²
K.E = 1/2 x 10kg x (10m/s)²
K.E = 0.5 x 10kg x (10m/s)²
K.E = 5 x 100
K.E = 500 joules
Thus, the kinetic energy of the ball is 500 joules
Answer: C. 1.64 x 10-3 m/s2
7. PE=0.5×700n/m×0.9m^2
0.9^2=0.81m
0.5×700×0.81= 283.5J
8. 2000=0.5×(x)×1.5m^2
1.5^2= 0.25
0.25×0.5=0.125
2000=0.125 (x)
2000/0.125=x
x=16000 n/m
9. 4000=0.5 (375 n/m)×(x)^2
0.5×187.5 (x)
4000/187.5=21.3333333333
1) Assuming an adult person has an average mass of m=80 kg, and assuming it takes about 30 seconds to climb 5 meters of stairs, the energy used by the person is

So the power output is

And since the estimate we made is very rough, we can say that the power output of the person is comparable to the power output of the light bulb of 100 W.
2) Based on the results we found in the previous part of the exercise, since the power output of the person is comparable to the power output of 1 light bulb of 100 W, we can say that the person could have kept burning only one 100-W light bulb during the climb.
<span>The support force is 15 N. The net force on the book is zero.</span>