Answer:1. Transparent
2. Transparent
3. Opaque
Explanation: In a transparent medium light can pass through. For opaque objects it does not allow to pass through instead it is reflected back.
Answer:
The right solution is:
(a) 2.87 eV
(b) 1.4375 eV
Explanation:
Given:
Wavelength,
= 433 nm
Potential difference,
= 1.43 V
Now,
(a)
The energy of photon will be:
E = 
= 
or,
= 
= 
(b)
As we know,
⇒ 
By substituting the values, we get
⇒ 
⇒ 
or,
⇒ 
⇒ 
Answer:
Answer: It takes 5,730 years for half the carbon-14 to change to nitrogen; this is the half-life of carbon-14. After another 5,730 years only one-quarter of the original carbon-14 will remain
All are true except the first two.
Answer:
68.5N
Explanation:
When the dolphin decelerates from 12m/s to 7.5 m/s within 2.3s. Then its acceleration is:

The dolphin has a mass of 35kg, according to the Newton's 2nd law, the force exerted on it must be:
