This is called average speed.Its really simple
Kinetic energy = mass time squared speed divided by 2
W=mv^2/2 = 50*10*10/2 = 2500 J
Answer:
Before: 0 m/s
After: -4 m/s
Explanation:
Before: Since you and your beau started at rest, your beau initial velocity is 0 m/s.
After: Since we have to conserve momentum,
momentum before push = momentum after push.
The momentum before push = 0 (since you and your beau are at rest)
momentum after push = m₁v₁ + m₂v₂ were m₁ = your mass = 60 kg, v₁ = your velocity after push = 3 m/s, m₂ = beau's mass = 45 kg and v₂ = beau's velocity.
So, m₁v₁ + m₂v₂ = 0
m₁v₁ = -m₂v₂
v₂ = -m₁v₁/m₂ = -60 kg × 3 m/s ÷ 45 kg = -4 m/s
So beau moves with a velocity of 4 m/s in the opposite direction
Answer: C
14.75g
Explanation:
Given that the half life time = 60.5s
Let No = initial mass = 59g
N = decayed mass
At time t = 0, No = 59g
At time t = 60.5s,
N = No/2 = 59/2
= 29.5g
At time t = 121
N = 29.5/2 = 14.75g
Therefore N = 14.75g
Answer:
7.53 m
Explanation:
Force, F = 47 N
initial velocity, u = 0
Final kinetic energy, Kf = 354 J
Let the distance traveled by the student is s.
According to the work energy theorem,
Work done by all forces = Change in kinetic energy
Force x distance = final kinetic energy - initial kinetic energy
F x s = kf - ki
47 x s = 354
s = 7.53 m