Answer:
B
Explanation:
nothing to do with black holes creating star or related
Answer:
4m/s2
Explanation:
The following data were obtained from the question:
U (initial velocity) = 10m/s
V (final velocity) = 30m/s
t (time) = 5secs
a (acceleration) =?
Acceleration is the rate of change of velocity with time. It is represented mathematically as:
a = (V - U)/t
Now, with this equation i.e
a = (V - U)/t, we can calculate the acceleration of the race car as follow:
a = (V - U)/t
a = (30 - 10)/5
a = 20/5
a = 4m/s2
Therefore, the acceleration of the race car is 4m/s2
Answer:
d. 37 °C
Explanation:
= mass of lump of metal = 250 g
= specific heat of lump of metal = 0.25 cal/g°C
= Initial temperature of lump of metal = 70 °C
= mass of water = 75 g
= specific heat of water = 1 cal/g°C
= Initial temperature of water = 20 °C
= mass of calorimeter = 500 g
= specific heat of calorimeter = 0.10 cal/g°C
= Initial temperature of calorimeter = 20 °C
= Final equilibrium temperature
Using conservation of heat
Heat lost by lump of metal = heat gained by water + heat gained by calorimeter

Answer: 7022.2kg/m³, yes, I was cheated
Explanation:
Density of an object is defined as the ratio of the mass of the object to its volume. Mathematically;
Density = Mass/Volume
Note that the unit of both mass and volume must be standard unit.
Given mass = 0.0158kg
Dimension of the metal = 5mm×15mm×30mm
Note that 1mm = 0.001m
The volume of the metal will be
0.005×0.015×0.03
= 0.00000225m³
Density = 0.0158/0.00000225
Average density of the metal = 7022.2kg/m³
Since the standard density of Gold is 19,320kg/m³ and is higher than the density prescribed for me, it shows the I was cheated.
To solve this problem we will use the trigonometric concepts to find the distance h, which will allow us to find the speed of Jeff and that will finally be the variable that will indicate the total tension, since it is the variable of the centrifugal Force given in the vine at the lowest poing of the swing.
From the image:


When Jeff reaches his lowest point his potential energy is converted to kinetic energy





Tension in the string at the lowest point is sum of weight of Jeff and the his centripetal force




Therefore the tension in the vine at the lowest point of the swing is 842.49N