Answer:
Yes, a sled has inertia while sitting still.
Explanation:
From Newton's law of inertia, an object at rest will remain at rest unless it is acted upon by an external force. The reason the object will remain at rest unless an external force acts is because of inertia. Inertia means the resistance of an object to motion.
Thus, a sled hammer at rest will remain at rest unless it is acted upon by an external force. So we can conclude that it has Inertia.
Answer:
13.41 horsepower
Explanation:
Power: This can be defined as the rate at which energy is used up by a body. The S.I unit of power is Watt (W).
The expression for power is given as,
P = Ek/t...................... Equation 1
Where P = power, Ek = Kinetic Energy of the car, t = time.
Recall that,
Ek = 1/2mΔv²............ Equation 2
Where m = mass of the car, Δv = change in velocity of the car.
Substitute equation 2 into equation 1
P = 1/2(mΔv²)/t...................... Equation 3
Given:m = 1000 kg, Δv = 30-20 = 10 m/s, t = 5 s
Substitute into equation 3
P = 1/2(1000×10²)/5
P = 10000 W.
If,
745.7 W = 1 hp,
Then,
10000 W = (10000/745.7) hp
= 13.41 hp.
P = 13.41 horsepower
Answer: Arrow B
Explanation:
Arrow B best best represents the path the ball follows after the string breaks.
This is because the described situation is related to <u>uniform circular motion</u>, in which the tangential velocity is the linear velocity vector that is <u>always tangent to the trajectory</u> and is the distance traveled by the ball in its circular motion in a period of time.
Hence, if this circular motion suddenly stops, the ball will fly in a direction that is tangent to that circle.
The electron’s speed when it reaches the positive plate is 2.65 X 10⁶m/s
<u>Explanation:</u>
Electric field strength, E = 20,000 N/C
Distance, x = 1 mm = 1 X 10⁻³m
Speed of the electron, s = ?
We know,
Charge of an electron, q = 1.602 X 10⁻¹⁹ C
So the force, F is
20000 N/C x 1.602 X 10⁻¹⁹ C = 3.2 X 10⁻¹⁵ Newtons
mass of electron is 9.1×10⁻³¹ kg
F = ma
a = 3.2 X 10⁻¹⁵ / 9.1 X 10⁻³¹ = 3.52 X 10¹⁵ m/s²
v = √(2ad) = √(2*3.52 X 10¹⁵ X 0.001) = 2.65 X 10⁶m/s
Therefore, the electron’s speed when it reaches the positive plate is 2.65 X 10⁶m/s