A force may cause an object to turn about a pivot. The turning effect of a force is called the moment of the force. Moments act about a pivot in a clockwise or anticlockwise direction.
Answer:
Specific heat capacity, c = 468.75 J/Kg°C
Explanation:
Given the following data;
Power = 1.5 kW to Watts = 1.5 * 1000 = 1500 Watts
Time = 5 seconds
Mass = 0.2 kg
Initial temperature = 20°C
Final temperature = 100°C
To find specific heat capacity;
First of all, we would have to determine the energy consumption of the kettle;
Energy = power * time
Energy = 1500 * 5
Energy = 7500 Joules
Next, we would calculate the specific heat capacity of water.
Heat capacity is given by the formula;
Where;
- Q represents the heat capacity or quantity of heat.
- m represents the mass of an object.
- c represents the specific heat capacity of water.
- dt represents the change in temperature.
dt = T2 - T1
dt = 100 - 20
dt = 80°C
Making c the subject of formula, we have;

Substituting into the equation, we have;


<em>Specific heat capacity, c = 468.75 J/Kg°C</em>
Answer:
If the combination of all the forces acting on an object sums upto be zero, then the net force is known as <u>balanced force.</u>
If the combination of all the forces acting on an object is non-zero, then the net force is said to be <u>unbalanced force. </u>The unbalanced force causes the object change the state of rest or motion.
Answer:
<em>Details in the explanation</em>
Explanation:
<u>Vertical Launch</u>
When an object is thrown vertically in free air (no friction), it moves upwards at its maximum speed while the acceleration of gravity starts to brake it. At a given time and height, the object stops in mid-air and starts to fall back to the launching point until reaching it with the same speed it was launched.
We are given an expression for the height of an object in function of time t

<em>Please note we have deleted the second 'squared' from the formula since it's incorrect and won't describe the motion of vertical launch.</em>
We now have to evaluate h for the following times, assuming h comes in feet
At t=1 sec

The object is at a height of 48 feet
At t=2 sec

The object is at a height of 64 feet. This is the maximum height the object will reach, as we'll see below
At t=3 sec

The object is at a height of 48 feet. We can clearly see it's returning from the maximum height and is going down
At t=4 sec

The object is at ground level and has returned to the launch point.
Answer:
Explanation:
We shall apply conservation of mechanical energy
kinetic energy of alpha particle is converted into electric potential energy.
1/2 mv² = k q₁q₂/d , d is closest distance
d = 2kq₁q₂ / mv²
= 2 x 9 x 10⁹ x 79e x 2e / 4mv²
= 1422 x2x (1.6 x 10⁻¹⁹)² x 10⁹ /4x 1.67 x 10⁻²⁷ x (1.5 x 10⁷)²
= 3640.32 x 10⁻²⁹ /2x 3.7575 x 10⁻¹³
= 484.4 x 10⁻¹⁶
=48.4 x 10⁻¹⁵ m