The correct answer to the question is : D) Be moving at a constant velocity.
EXPLANATION:
As per Newton's first laws of motion, every body continues to be at state of rest or of uniform motion in a straight line unless and until it is compelled by some external unbalanced forces acting on it.
Hence, it is the unbalanced force which changes the state of rest or motion of a body. Balanced force is responsible for keeping the body to be either in static equilibrium or in dynamic equilibrium.
As per the options given in the question, the last one is true for an object under balanced forces.
Answer: V = 15 m/s
Explanation:
As stationary speed gun emits a microwave beam at 2.10*10^10Hz. It reflects off a car and returns 1030 Hz higher. The observed frequency the car will be experiencing will be addition of the two frequency. That is,
F = 2.1 × 10^10 + 1030 = 2.100000103×10^10Hz
Using doppler effect formula
F = C/ ( C - V) × f
Where
F = observed frequency
f = source frequency
C = speed of light = 3×10^8
V = speed of the car
Substitute all the parameters into the formula
2.100000103×10^10 = 3×10^8/(3×10^8 -V) × 2.1×10^10
2.100000103×10^10/2.1×10^10 = 3×108/(3×10^8 - V)
1.000000049 = 3×10^8/(3×10^8 - V)
Cross multiply
300000014.7 - 1.000000049V = 3×10^8
Collect the like terms
1.000000049V = 14.71429
Make V the subject of formula
V = 14.71429/1.000000049
V = 14.7 m/s
The speed of the car is 15 m/s approximately.
Newton's 2nd law says: Force = (mass) x (acceleration) .
I wrote Force and acceleration in bold letters because
they're both vectors ... they have size and direction.
The equation is saying that the Force and the acceleration
are both in the same direction.
Answer:
Explanation:
Let the amplitude of individual wave be I and resultant amplitude be 1.703 I . Let the phase difference be Ф in terms of degree
From the formula of resultant vector
(1.703I)² = I² + I² + 2 I² cosФ
2.9 I² = 2I² + 2 I² cosФ
.9I² = 2 I² cosФ
cosФ = .9 / 2
= .45
Ф = 63.25 .
Answer:
8 m/s²
Explanation:
Given,
Force ( F ) = 4 N
Mass ( m ) = 0.5 kg
To find : -
Acceleration ( a ) = ?
Formula : -
F = ma
a = F / m
= 4 / 0.5
= 40 / 5
a = 8 m/s²
It's acceleration is 8 m/s².
