Answer:
4m
Explanation:
you divide 20m/s by 5 seconds
Answer:
2 m/s
Explanation:
Parameters given:
Mass of first skateboard, m = 3 kg
Initial speed of first skateboard, u = 4 m/s
Mass of second skateboard, M = 1 kg
Initial speed of second skateboard, U = 0 m/s
Final speed of second skateboard, V = 6 m/s
Using the principle of the conservaton of momentum, the total initial momentum is equal to the total final momentum.
Momentum is the product of mass and velocity. This implies that:
m*u + M*U = m*v + M*V
(3*4) + (1*0) = (3*v) + (1*6)
12 + 0 = 3v + 6
=> 3v = 12 - 6
3v = 6
v = 6/3 = 2 m/s
The final speed of the 3 kg skateboard is 2 m/s
Answer:
1.25 m
0.5 s
Explanation:
Given:
v₀ = 5 m/s
v = 0 m/s
a = -10 m/s²
Find: Δy
v² = v₀² + 2aΔy
(0 m/s)² = (5 m/s)² + 2 (-10 m/s²) Δy
Δy = 1.25 m
Find: t
v = at + v₀
(0 m/s) = (-10 m/s²) t + (5 m/s)
t = 0.5 s
Answer:
625 N
Explanation:
The impulse given to the nail is equal to the change in momentum of the hammer:
where
F is the force exerted by the hammer
is the time of contact
is the mass
is the change in velocity of the hammer
Substituting the data and re-arranging the equation, we can find the force:
Explanation:
Given data
Mass of skier m=65kg
Height of slope =80m
Potential energy possessed by the skier (positive work done) =12000J
Analysing his energy at half way point on the hill
Potential energy will be equal to kinetic energy
Applying the conservative principles of energy when the skier is at half way point in the hill
I.e
mgh= 1/2mv²
The masses will cancel out
gh=v²
Given g= 9.81m/s²
Let's solve for the velocity
v²=9.81*80
v=√784.8
v=28.0m/s
Now we can solve for the kinetic energy
KE= 1/2mv²
KE =1/2*60*28²
KE =47063.9/2
KE=23531.9J
Hence we can calculate the energy gained by the skier during his movement
Energy gained = KE-PE
= 23531.9-12000
= 11531.9J
