The law applied here is Newton's first law, also known as, law of inertia.
This law states that: A body will retain its state of rest or motion unless acted upon by an external force.
If you are moving and the bus suddenly stops, your body will lurch forward trying to retain its state of motion until it comes to rest and changes its state by the external force acted on it.
If you are at rest and the bus suddenly moves, your body will lurch backwards trying to retain its state of rest and opposing the force of motion until it is forced to change its state by this force.
Answer:
a = 10 m/s²
Explanation:
<u><em>Given:</em></u>
Force = F = 50 N
Mass = m = 5 kg
<u><em>Required:</em></u>
Acceleration = a = ?
<u><em>Formula:</em></u>
F = ma
<u><em>Solution:</em></u>
<em>Rearranging the formula for a</em>
=> a = F/m
=> a = 50/5
=> a = 10 m/s²
<span>Voltage overcomes the resistance of the electromagnet winding to force a current through that resistance. The field strength is proportional to the coil current. More voltage pushes more current. More voltage builds up the current faster, as well as forcing it to a higher final value. </span>
Answer:
2025000 J
Explanation:
The formula for kinetic energy is KE=.5(m)(v²).
The initial kinetic energy is 0 because it is at rest. .5(m)(0) = 0.
To calculate the final kinetic energy, use the kinetic energy equation. KE = .5(2000)(45²) = 2025000 J.
To find the change in kinetic energy, you do KE(f) - KE(i). 2025000-0 = 2025000 J.
Explanation:
Elongation of the wire is:
ΔL = F L₀ / (E A)
where F is the force,
L₀ is the initial length,
E is Young's modulus,
and A is the cross sectional area.
ΔL = T (0.5 m) / ((2.0×10¹¹ Pa) (0.02 cm²) (1 m / 100 cm)²)
ΔL = T (1.25×10⁻⁶ m/N)
T = (80,000 N/m) ΔL
Draw a free body diagram of the mass at the bottom of the circle. There are two forces: tension force T pulling up and weight force mg pulling down.
Sum of forces in the centripetal direction:
∑F = ma
T − mg = mv²/r
T − mg = mω²r
T − (15 kg) (9.8 m/s²) = (15 kg) (2 rev/s × 2π rad/rev)² (0.5 m + ΔL)
T − 147 N = (2368.7 N/m) (0.5 m + ΔL)
Substitute:
(80,000 N/m) ΔL − 147 N = (2368.7 N/m) (0.5 m + ΔL)
(80,000 N/m) ΔL − 147 N = 1184.35 N + (2368.7 N/m) ΔL
(797631.3 N/m) ΔL = 1331.35 N
ΔL = 0.00167 m
ΔL = 1.67 mm
