The car's velocity after 5s : 10 m/s
<h3>Further explanation</h3>
Given
velocity=v=72 km/h=20 m/s
time=t = 5 s
acceleration=a = -2 m/s²
Required
velocity after 5s
Solution
Straight motion changes with constant acceleration

vf=final velocity
vi = initial velocity
Input the value :

The car is decelerating (acceleration is negative) so that its speed decreases
Answer:
C.
Explanation:
Specific heat capacity of a substance can be defined as the amount of heat a gram of the substance must lose or absorb in order to change its temperature by a degree Celsius. It is measured in Joules per kilogram per degree Celsius (J/kg°C).
Generally, the specific heat capacity of water is 4.182J/kg°C and is the highest among liquids.
Heat capacity or quantity of heat 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 the substance.
dt represents the change in temperature.
Hence in calculating the relationship between the amount of heat added to a substance and the corresponding temperature change, the specific heat capacity is usually represented by the symbol C.
Answer:
Heat required = 1.23×10⁵J
Explanation:
Given:
Mass (m) = 500 gram
Specific heat = 6,090 J/g
heat of fusion = 247 J/g.
Find:
Heat required
Computation:
Heat required = 247 J/g× 500 g
Heat required = 1.23×10⁵J