as per the question charlie runs to the store which is 4 km away
hence the total distance covered [S] is 4 km
he takes 30 minutes to reach the store.
hence the total time taken [t] = 30 minutes=0.5 hour
We have to calculate the average speed.
the average speed[v]= 
=
=8 km/hour
then we have to calculate the total distance traveled by charlie in 1 hour.
the distance covered S= 
=8 km/hour ×1 hour
=8 km
Hence the average speed of charlie is 8 km/hour and he covers a distance of 8 km in 1 hour.
Answer: 2.67 m/s
Explanation:
Given
Mass of block A is 
mass of block B is 
The initial velocity of block A 
the initial velocity of block B is 
After collision velocity of block A is 
Conserving momentum

The momentum of block A after the collision is 
Therefore, there is no change in sign.
The magnification of the ornament is 0.25
To calculate the magnification of the ornament, first, we need to find the image distance.
Formula:
- 1/f = u⁻¹+v⁻¹.................... Equation 1
Where:
- f = Focal length of the ornament
- u = image distance
- v = object distance.
make u the subject of the equation
- u = fv/(f+v)................ Equation 2
From the question,
Given:
Substitute these values into equation 2
- u = (12×4)/(12+4)
- u = 48/16
- u = 3 cm.
Finally, to get the magnification of the ornament, we use the formula below.
- M = u/v.................. Equation 3
Where
- M = magnification of the ornament.
Substitute these values above into equation 3
Hence, The magnification of the ornament is 0.25
<span>B. velocity .................</span>
Answer:
162.8 K
Explanation:
initial current = io
final current, i = io/8
Let the potential difference is V.
coefficient of resistivity, α = 43 x 10^-3 /K
Let the resistance is R and the final resistance is Ro.
The resistance varies with temperature
R = Ro ( 1 + α ΔT)
V/i = V/io (1 + α ΔT )
8 = 1 + 43 x 10^-3 x ΔT
7 = 43 x 10^-3 x ΔT
ΔT = 162.8 K
Thus, the rise in temperature is 162.8 K.