Answer:
W = 47040 J
Explanation:
Given that,
The mass of a student, m = 60 kg
Height of the tower, h = 80 m
We need to find the work done in climbing the tower. The work done is given by :
W = mgh
So,
W = 60 × 9.8 × 80
W = 47040 J
So, the required work done is 47040 J.
Answer
given,
Side of copper plate, L = 55 cm
Electric field, E = 82 kN/C
a) Charge density,σ = ?
using expression of charge density
σ = E x ε₀
ε₀ is Permittivity of free space = 8.85 x 10⁻¹² C²/Nm²
now,
σ = 82 x 10³ x 8.85 x 10⁻¹²
σ = 725.7 x 10⁻⁹ C/m²
σ = 725.7 nC/m²
change density on the plates are 725.7 nC/m² and -725.7 nC/m²
b) Total change on each faces
Q = σ A
Q = 725.7 x 10⁻⁹ x 0.55²
Q = 219.52 nC
Hence, charges on the faces of the plate are 219.52 nC and -219.52 nC
Answer:
Speed of the boat, v = 4.31 m/s
Explanation:
Given that,
Height of the bridge, h = 32 m
The model boat is 11 m from the point of impact when the key was released, d = 11 m
Firstly, we will find the time needed for the boat to get in this position using second equation of motion as :

Here, u = 0 and a = g


t = 2.55 seconds
Let v is the speed of the boat. It can be calculated as :


v = 4.31 m/s
So, the speed of the boat is 4.31 m/s. Hence, this is the required solution.
The ground exerts an equal force on the golf ball.
Answer:

Explanation:
What problem says can be written mathematically as:

Where:

The problem itself it's really simple, we only need to replace the data provided in the previous equation, but first, let's convert the units of the velocity from cm/s to m/s because we have to work with the same units and working in meters is the most apropiate action, because is the base unit of length in the International System of Units:

Now, we can replace the data in the equation and find the time it will take the bird to travel 3.7 m:

Solving for t, multiplying by t both sides, and dividing by 0.52 both sides:
