Answer: 0.24g/ml
Explanation:
Given that:
Volume of water displaced = 23.5 ml
Mass of cork = 5.7 g
Density of the cork = ?
Recall that density is obtained by dividing the mass of a substance by the volume of water displaced.
i.e Density = Mass/volume
Density = 5.7g /23.5ml
Density = 0.24g/ml
Thus, the density of the piece of cork is 0.24g/ml
The average speed of the car for the entire trip can be calculate by using:

where S is the total distance covered by the car, and t is the total time taken.
The total distance travelled by the car is:

while the total time taken is:

so, the average speed of the car is:

so, the correct answer is (3) 85 km/h.
Answer:
T
Explanation:
= magnitude of current in each wire = 2.0 A
= length of the side of the square = 4 cm = 0.04 m
= length of the diagonal of the square =
a =
(0.04) = 0.057 m
= magnitude of magnetic field by wires at A and C


T
= magnitude of magnetic field by wire at B


T
Net magnitude of the magnetic field at D is given as



T