Answer:
b. 1.1 m
Explanation:
It is given that the total distance between the masses is equal to the length of the board, which is 3 m. Therefore,
where,
s₁ = distance of fulcrum from left mass
s₂ = distance of fulcrum from right mass
In order to achieve balance, the torque due to both masses must be equal:
s₁ = 1.1 m
Hence, the correct option is:
<u>b. 1.1 m</u>
The density of the material would be 4.1 g/cm³.
Density is calculated by dividing the mass by the volume.
D=m÷v
D=45 g÷11 cm³
D=4.1 g/cm³
Answer:
the potential energy is 114 J.
Explanation:
Given;
total mechanical energy, E = 400 J
kinetic energy, K.E = 286 J
The potential energy is calculated as follows;
E = K.E + P.E
where;
P.E is the potential energy
P.E = E - K.E
P.E = 400 J - 286 J
P.E = 114 J
Therefore, the potential energy is 114 J.
Answer:
1. 3 m
2. 27 s
Explanation:
1. "A car traveling at +33 m/s sees a red light and has to stop. If the driver can accelerate at -5.5 m/s², how far does it travel?"
Given:
v₀ = 33 m/s
v = 0 m/s
a = -5.5 m/s²
Unknown: Δx
To determine the equation you need, look for which variable you don't have and aren't solving for. In this case, we aren't given time and aren't solving for time. So look for an equation that doesn't have t in it.
Equation: v² = v₀² + 2aΔx
Substitute and solve:
(0 m/s)² = (33 m/s)² + 2(-5.5 m/s²) Δx
Δx = 3 m
2. "A plane starting from rest at one end of a runway accelerates at 4.8 m/s² for 1800 m. How long did it take to accelerate?"
Given:
v₀ = 0 m/s
a = 4.8 m/s²
Δx = 1800 m
Unknown: t
Equation: Δx = v₀ t + ½ a t²
Substitute and solve:
1800 m = (0 m/s) t + ½ (4.8 m/s²) t²
t ≈ 27 s
Impulse = change in momentum
The car's momentum was (mass) x (speed)
Momentum = (2400 kg) x (20 m/s)
Momentum = 48,000 km-m/s
To completely stop the car, the impulse = -48,000 km-m/s .
