Answer:
a. If an object's speed is constant, then its acceleration must be zero.
FALSE
As we know that acceleration is defined as the rate of change in velocity

so we can not say anything about the acceleration when speed is given to as and no information is given about velocity
b. If an object's acceleration is zero, then its speed must be constant.
TRUE
As we know that acceleration is defined as the rate of change in velocity

Since we know that if acceleration is 0 then velocity must be constant and hence speed is also constant
c. If an object's velocity is constant, then its speed must be constant.
TRUE
Since velocity is constant then it shows that its magnitude and direction both are constant so its speed is also constant.
d. If an object's acceleration is zero, its velocity must be constant.
TRUE
As we know that acceleration is defined as the rate of change in velocity

Since we know that if acceleration is 0 then velocity must be constant
e. If an object's speed is constant, then its velocity must be constant.
FALSE
Speed is just the magnitude so we can not say about its direction and hence if speed is constant then velocity may or may not change
Answer:
75degree don't forget wind and gravity force pulling down
Answer:
Therefore the ratio of diameter of the copper to that of the tungsten is

Explanation:
Resistance: Resistance is defined to the ratio of voltage to the electricity.
The resistance of a wire is
- directly proportional to its length i.e

- inversely proportional to its cross section area i.e

Therefore

ρ is the resistivity.
The unit of resistance is ohm (Ω).
The resistivity of copper(ρ₁) is 1.68×10⁻⁸ ohm-m
The resistivity of tungsten(ρ₂) is 5.6×10⁻⁸ ohm-m
For copper:


......(1)
Again for tungsten:

........(2)
Given that
and 
Dividing the equation (1) and (2)

[since
and
]



Therefore the ratio of diameter of the copper to that of the tungsten is

Answer:
Angular acceleration = 6.37rad/sec²
Approximately, Angular acceleration =
6.4 rad/sec²
Explanation:
Length of the rod = 2.0m long
Inclination of the rod (horizontal) = 30°
Mass of the rod is not given so we would refer to it as = M
Rotational Inertia of the Rod(I) = 1/3ML²
Angular Acceleration = ?
There is an equation that shows us the relationship between Torque and Angular acceleration.
The equation is :
Torque(T) = Inertia × Angular Acceleration
Angular acceleration = Torque ÷ Inertia
Where:
Torque = L/2(MgCosθ)
Where M = Mass
L = Length = 2.0m
θ = Inclination of the rod (horizontal) = 30°
g = Acceleration due to gravity = 9.81m/s²
Inertia = 1/3ML²
Angular Acceleration = (Mass × g × Cos (30°) × (L÷2)) ÷ 1/3ML²
Angular Acceleration =
(3 × g × cos 30°) ÷ 2× L
Angular Acceleration = (3 × 9.81m/s² × cos 30°) ÷ 2× L
Angular Acceleration = 3 × 9.81m/s² × cos 30°) ÷ 2× 2.0m
Angular Acceleration = 6.37rad/sec²
Approximately Angular Acceleration =
6.4rad/sec²
Answer:
screw and pulley
Explanation:
because they didn't have any of the other tools in that time