The answer is 570 J. The kinetic energy has the formula of 1/2mV². The total work in this process W= 1/2m(V2²-V1²) = 1/2 * 15.0 * (11.5²-7.50²) = 570 J.
Answer:
H = 171.90 m
Explanation:
given data
distance = 53.2 m
height = H
to find out
height H
solution
we know height is here H =
......................1
here t is time and a is acceleration
so
we find t first
we know during time (t -1) s , it fall distance (H - 53.2) m
so equation of distance


................2
now subtract equation 2 from equation 1 so we get
53.2 = gt - 
53.2 = 9.81 t - 
t = 5.92 s
so from equation 1
H =
H = 171.90 m
Answer:
R = 4.24 x 10⁻⁴ m
Explanation:
given,
mass of the person = 60.3-kg
mass of the bullet = 10 gram = 0.01 Kg
velocity of bullet = 389 m/s
angle made with the horizontal = 45°
using conservation of momentum.
M v + m u = ( M + m ) V
60.3 x 0 + 0.01 x 389 = (60.3 + 0.01) V


V = 0.0645 m/s
for calculation of range


R = 4.24 x 10⁻⁴ m
the distance actor fall is R = 4.24 x 10⁻⁴ m
Answer:
180 W
Explanation:
The work done by the man against gravity is equal to its gain in gravitational potential energy:

where
(mg) = 720 N is the weight of the man
is the change in height
Substituting,

The power he must deliver is given by

where
W = 3600 J
t = 20 s is the time taken
Substituting,
