Answer:
a) 30J
Explanation:
use formula first find K.E with both speeds
K.E. = 1/2 m v2
and then
work done= change in kinetic energy
Answer:
a = 1 m/s²
Explanation:
given,
mass of the person = 60 Kg
Net External force exerted = 90 N
force of friction opposing the motion = 30 N
acceleration of the box = ?
Net force = External force applied - frictional force
Net force = 90 - 30
net force = 60 N
we know
F = mass x acceleration
60 = 60 x a
a = 1 m/s²
acceleration of the box is equal to a = 1 m/s²
Answer:
1800 N
Solution:
Impulse = mΔv = m * (u - v) .
here m = 100 kg
u = 4 m/s
v = -5 m/s
impulse = 100 x ( 4 - ( -5 ) ) = 900 Kg m/s .
Average reaction Force ( Favg ) = impulse / Δt
Average reaction Force ( Favg ) = 900kg·m/s / 0.5s
Average reaction Force ( Favg ) = 1800 N
Answer:
0.338125 m/s
Explanation:
Applying,
Law of conservation of momentum
m'v' = mv............ Equation 1
Where m' = mass of the first skater, v' = velocity of the first skater, m = mass of the second skater, v = velocity of the second skater.
make v the subject of the equation
v = m'v'/m........... Equation 2
From the question,
Given: m' = 54.1 kg, v' = 0.375 m/s, m = 60 kg
Substitute these values into equation
v = (54.1×0.375)/60
v = 20.2875/60
v = 0.338125 m/s
