Let's go through your questions one by one:
Question 16: Acceleration of the soccer ball To find the acceleration \( a \), we can use Newton's second law: \[ F = m \cdot a \] Where:
- \( F = 0.90 , \text{N} \) (force)
- \( m = 0.350 , \text{kg} \) (mass)
Rearranging the formula to find acceleration: \[ a = \frac{F}{m} = \frac{0.90 , \text{N}}{0.350 , \text{kg}} \approx 2.57 , \text{m/s}^2 \]
Thus, the correct answer is: e. 2.6 m/s² (rounded).
Question 17: Distance traveled by the dolphin To calculate the distance traveled, we can use the formula: \[ \text{Distance} = \text{Speed} \times \text{Time} \] Where:
- Speed = \( 1.85 , \text{m/s} \)
- Time = \( 6.0 , \text{s} \)
Calculating: \[ \text{Distance} = 1.85 , \text{m/s} \times 6.0 , \text{s} = 11.1 , \text{m} \]
The closest answer is: a. 11 m.
Question 18: Gravitational force of attraction To find the gravitational force, we can use: \[ F = m \cdot g \] Where:
- \( m = 17 , \text{kg} \) (mass)
- \( g = 8.8 , \text{m/s}^2 \) (acceleration due to gravity)
Calculating: \[ F = 17 , \text{kg} \times 8.8 , \text{m/s}^2 = 149.6 , \text{N} \]
Rounding gives approximately: c. 150 N.
Question 19: Type of nuclear radiation Given the reaction: \[ \frac{35}{16} \text{S} \rightarrow \text{?} + \frac{35}{17} \text{Cl} \] This indicates that a beta particle (an electron) is emitted, which increases the atomic number by 1 while keeping the mass number the same.
So, the type of radiation is: c. Beta radiation.
Question 20: Number of half-lives To calculate how many half-lives have occurred in 67.5 hours with a half-life of 7.5 hours: \[ \text{Number of half-lives} = \frac{\text{Total time}}{\text{Half-life}} = \frac{67.5 , \text{hours}}{7.5 , \text{hours}} = 9 \]
Thus, the correct answer is: c. 9 half-lives.
In summary, the answers are:
16. e. 2.6 m/s²
17. a. 11 m
18. c. 150 N
19. c. Beta radiation
20. c. 9 half-lives